Biology

Biology

Known as the hermit beetle since the entire life cycle can take place within the hollow of just one tree, this elusive species spends three to four years as a larva, feeding on the rotten wood in the centre of the hollow (2). It pupates in autumn, constructing a cocoon out of its excrement and wood mould, and then emerges as a beetle the following summer (4). Dispersal is limited, as although the beetles can fly, very few do, and even then, rarely further than 100 metres. For this reason the beetles require a stable environment with suitable habitat very nearby (2). Usually, adult hermit beetles are found from July to September (4). In field studies, the lifespan of adults has been up to one month, while in the lab, hermit beetles, especially females, may survive much longer (4). The most important predator of hermit beetle larvae is probably the larvae of the click beetle (Elater ferrugineus), and they can also be infested with mites and nematodes. Occasional predation by vertebrates on hermit beetles has also been reported (4).